Paper-bag-making machine



March 24, 1925.

J. DUVALL PAPER BAG MAKING MACHINE Filed July 13. 1922' 3 Sheets-Sheet 1 JZzmew .Dl/ual/ March 24, 1925.

J. DUVALL I PAPER BAG MAKING MACHINE Filed July 13, 1922 3 Sheets-Sheet 2 mm u v March 24, 1925.

J. DU VALL PAPER BAG MAKING MACHINE 3 Shee ts-Sheet 5 Filed July 15 1922 J5/7; as 2700 a// Patented Mar. 24, 1925.

PATENT emceumms 'nUvALL, or cums, WASHINGTON.

rumpus-Maxine ,4

Application filed July 13, 1922. Serial No. 514,069.

To all whom it may concern:

Be it known that I, JAMES DUvALL, a

citizens of the. United States, and a resident of Camas, county of Clark, and State of- Washington, have invented a new and useful Improvement in .Paper-Bag-Making j Machines, of which the following is a specistructed frequentl against the path of motion of the moving fication.

My invention concerns paper bag. making machines in which an endless tube of paperis formed and fed thru the machine, and cut into suitable sections corresponding to the length of the bag,-andmy inone wall of the bellows or side fold of the tube will be torn instead of cut, as illustrated by Fig. 8. Hence two imperfect bags would result. One wall of the bellows at the tube end a, when out was left with a torn out piece I) which overlapped a corner of the pasting-lip 0. Therefore where this bag end'is folded over and pasted down to make the closed end of the bag, such end will be imperfectly closed and permit granular or powdered material to run out..

At the same time the bag end 03 has a piece torn out'and gives it an imperfect appearance. v

One of the main objects of my invention is to provide a striker arm which is adapted to operate" adjacent the edges of the serrated blades and wholly in a plane transverse to the path of the motion' of said tube and inclined towards the said cutting -edges. Thus the striker arm operates first to impale the walls of. said tube upon the serrations of said edges, and thus partially to sever one section of the tube from the other and then by continued operation of said striker arm to complete the severing of said tube sections. In other words the action of the striker arm is directed tube of-paper.

A further object is to provide mecha nism which will produce a slack in the tube of paper passing thru the machine forward "and the feed rolls.

of the feed rolls. This is preferably accomplished in my mechanism by placing a pair of pinch rolls'forward of the feed rolls, the pinch rolls adapted 'to have operative contact with each other for an interval in each revolution only, and are rotated at a lesser rate than the feed rolls and thus while the rolls are in operative contact they produce a slack in the tube'section between them This slacking action is ti'medso as to occur immediately preceding and during the act of severing by the striker arm, and thus permits the paper to be first impaled u on the serrations of the cutting edges, before the force of the striking arm completes the severing of the tube section. V

.'A further object is to arrange the blade of the striker arm so that its longitudinal dimension will notbe parallel to the tube of the paper at the instant of impact. That.

is,that the blade of the striker arm will not strike the moving tube of paper and sever it at a single'blow, but the blade will sever oneportionlof the bag first, and in the continuation of the stroke successively sever the remaining portions. In short, in

this way a shearing action is produced on the .ser'rating. edges instead of a breaking action, and thus the impact and therefore vibration due to the cutting action will be substantially reduced. The elimination of this vibration will greatly lengthen the life of the paper bag making machine, and also will cause the severing of the tube'section to be made uniformly, thus preventingany ragged edges from interfering with the pasting of the bottom. fold of. the finished These and other objects I have shown in the accompanying drawings, in which: v

Fig. 1 is a fragmentary plan view of a paper machine embodying my cutting mechanism and indicates by arrows the path of the striker arm;

Fig. 2 is a fragmentary longitudinal sec tion and shows in dotted lines the path of the striker arm and illustrates the fact that the striker arm passes the .serrating teeth at a decided angle;

Fig. 3 is a view taken on the line 33 of Fig. 1 and the arrows show the path of motion of the striker-arm in relation to the serrating teeth; v

Fig; 4 is a fragmentary side elevation of my device and shows that the striker arm chine;

Fig. 5 is a diagrammatic section which shows how the upward rotation of the strik er-arm first impales the paper on the serrations due to the slack in the web;

Figs. 6 and 7 are side elevations of types of striker arms which strike the paper so that their longitudinal dimensions are not parallel to the tube of paper at the instant of impact;

Fi 8 is a diagrammatic representation of a jacent bag sections and illustrates how one cut severs the bottom of one bag from the top of the adjacent one;

Fig. 9 is a diagrammatic representation of the bottom of a bag section which has been out perfectly; and

Fig. 10 is a similar diagram showing a section which has a portion which is not.

severed correctly.

The construction of my machlne is as follows: The drawings show merely the part of the paper machine which specifically relates to my invention, namely, that of the cuttin mechanism. No claim is made for any ot er parts of the machine which are of standard construction.

In this type of paper machine a web of paper of suitable width is first converted into a bellow-sided tube having its sides folded inward like the side of a bellows. This tube forming mechanism consists of an internal former provided with a recess in its sides into which the paper is guided to form these bellows folds of the tubes and external guides or fingers which operate to fold the paper around the former into its lateral recess. The paper is fed to the cutter barin this type as a continuous web of paper formed as a tube, and made with a pasted center seam. The machine is made with a frame 1 and the ends of the former plates are shown as 2, 3, and .4. The plate 3 pinches the inward folding part of the bellows fold between its under side and the plate 5 and the former plates 2 and 4 extend into the outward fold of this type and keep the bag flat. The former plates 3 and 4 extend to within a short distance of thefeed rollers g and 7. The rollers 6 and 7 are journaledin the frame 1 and are formed with broad circumferential ribs 6 and 7 respectively which define a broad circumferential groove between them, and the groove prevents the surface of the rolls from contacting against the upper and lower sides of the former plate 2 which is reduced in width and extends thru the rolls in this groove and the end of which forms one of the serra ing edges as 8. The other serrating edge as 9 which forms the upper set of serrating teeth is mounted to the frame 1 adjacent the upper feed roller.

The tube of paper after being formed and The former plate 2 which-has been re- I duced in width so as to pass between the rolls without interfering with their positive bite upon the tube is restoredto its full width upon passing thru these rolls 6 and 7 and terminates in a serrating edge 8. The upper serrating edge 9 is mounted to a transverse bar 9 which is mounted across the top of the frame 1 and provides a rigid support for the serrating plate. This bar lies a short distance in front of the pinch rolls 6 and 7 and a slight distance above'the former plate 2. As the tube is advanced b the rolls 6 and 7 its end will pass beneath the plate 9 and ofi the end .of

former plate 2 after which it continues to advance until a sufiicient length of the tube for the formation of a bag is past the cutting edges 8 and 9.

The cutter mechanism with which this application is concerned is mounted directly behind these feed rollers and is inclined approximately 45 to the horizontal. The striker arm mechanism consists of a rotatable shaft 10 which has a miter gear 11 on one end and the striker 12 on the other. It is journaled in the bearing 13 which is fastened to the frame 1. The miter gear 11 meshes with the driven miter gear Hand is driven by the same. The'striker arm 12 is made with a blade 12 or 12 and a counterweight 12". The blade may be separate and held to the main body of the striker arm 12 by cap screws 15. The blade is a flat piece of metal and is arranged to rotate side ways so that the side of the bar strikes the paper and causes the cutting action. The cutting blade is preferably made tapered as 12 or concave as 12 so that the blade will strike the paper angularly and the paper will be severed with a gradual clear out rather than a fiat striking cut.

.In the operation of severing, the under ply of the tube is severed by the edge 8 and the upper ply by the edge 9 and as the latter of these. edges is somewhat in the rear of the former the result is that the plies are not severed evenly, but that the lower ply of the advancing end of the tube is left extending some distance along the upper. This fact enables both plies to be pasted to the body of the bag when the bottom is .a perfect seam on the bottom of the bag.

The pinch rolls 16 and 17 are positioned in the bearings mounted in the frame 1 immediately behind the cutter mechanism and are adapted to hold one end of the section of the web durin the cutting operation. The roll 16 is ma c with a-lip 16 whlch is adapted to grip the web passing thru for a short time durin every rotation. These rolls are timed so t at this lip grasps the paper shortly before the cutter strikes and severs the same. These rollers are run at substantially less speed than the feed roller 7 and thus when the lip 16 is grlpping the paper the difference in speed will cause the paper passing between the feed rolls and the pinch rolls to slack. This action is timed so as to happen just before the striking bar hits the paper and thus there is a considerable slack which allows the cutter bar to force the paper/against the teeth and thus causing the serrating teeth to be forced thru the paper before the actual cutting operation commences and thus a cleaner, more positive cut is attalned w1thout the attendant vibration which is so noticeable in machines as now constructed. The creasing rolls 18 and 19 are 3ournaled in the frame 1 immediately behind the pinch rolls 16 and 17 and are driven at a rate slightly greater than the rolls 6 and 7 and are adapted to gri the cut section of the tube and pull t e same thru the pinch rolls before the lip 16 again comes in contact with the roll 17 and thus one section of the tube is removed from the cutting mechanism before the next section is gripped to be cut. The roll 18 has an incision 20 and the roll 19 has an incision 21 which are adapted to grip the ends of the tube and make the end fold.

An idling roll 22 mounted on an arm 23 bears against the roll 19 and completes the crease made by the incisions 20 and 21. The roll 22 is held against the roll 19 by the spring 24 pulling on the opposite end of the arm 23.

The cuttingmechanism of paper machines, as now constructed, involves a striker arm, the path of which at the mstant of scrration, is normal to the web of paper. This causes the paper to be broken suddenly which causes a decided vibration in the machine and also limits the output of the machine.

The fixed or serrator blades have been made with saw edges and the force of the blow of the striker tends to cause the paper to break across these teeth. There is no definite and certain result however, and if there is some imperfection in the web of paper the break may not occur on the serrating blade because the tension on the paper is uniform thruout.

In the device embodying my inventionI have designed the striking blade so that it will strike the paper at a decided angle and thus impale the paper on the teeth of the serrating plates. When the paper is forced upward by the continued stroke of the blade the paper is broken to such a degree that it is by far the weakest point in the tube of paper and thus the break is certain and clean cut. To make sure that the paper will not break when the striker blade first strikes the paper I have devised and timed the mechanism so that the web is slackened slightly by the pinch rolls and thus the ress rolls force paper by the serrating lade faster thanthe pinch rolls take it away. The paper is thus-slacked oflf'and thus when the cutter bar makes the slack paper taut the serrating teeth are first forced thru the paper.

The paper is thus torn gradually and not broken and this tearing action is further accentuated in that the blade of the cutter bar is slightly hollowed and thus one part strikes the paper before the other and thus tears the paper first. This combined action causes a substantial elimination of the vibration in the machine and thus goes for greater rigidity and durability besides increased output.

I claim:

1.. In a paper bag making machine, material severing mechanism comprisin a fixed knife edge at one side of the pat of the sheet of material, and a rotated striker arm arranged .to strike the opposite side of the sheet, to sever the same upon said knife edge, said striker arm rotating wholly within a plane intersecting the path of said sheet at such an angle relatively to said knife edge, and against the direction of movement thereof, that the striker arm tends to bend the sheet backwardly over 3. In a paper bag making machine, material severing mechanism comprising a fixed knife edge atone side of the path of the sheet of material, and a rotated striker arm arranged-to strike the-opposite side of the sheet, to sever the same upon said knife edge, said striker arm rotating wholly within a plane intersecting the. path of said sheet at such an angle relatively to said knife edge, and against the direction of movement thereof, that the striker arm tends to bend the sheet backwardly over said knife edge and means for causing a slack in said sheet at the instant of impact of said striker arm therewith, thereby to permit the sheet to be bent back over said' knife edge a substantial distance and at a relatively sharp angle.

4. In a paper bag making machine, mate rial severing mechanism, comprising a fixed knife edge at one side of the path of the sheet of material, and a rotated striker arm arranged to strike the opposite side of the sheet, to sever the same upon said knife edge, said striker arm rotating wholly within a plane intersecting the path of said sheet at such an angle relatively to said knife edge and against the direction of movement thereof, that the striker arm tends to bend the sheet hackwardly over said knife edge, means for causing a slack in said sheet at the instant of impact of said striker arm 20 therewith, thereby to permit the sheet to be bent back over said knife edge a substantial distance and at a relatively sharp angle, the knife edge being serrated whereby the bending back of said sheet upon said cutting edge causes the serrations first to puncture the sheet, and then to break the portions of said sheet between said perforations, by the continued pull of said striker .arm thereon.

5. In a paper bag making machine, material severing mechanism comprisin a fixed knife edge at one side of the pat of the sheet of material, and a rotated striker armarranged to strike the opposite side of the sheet, to sever the same upon said knife edge, said striker arm being mounted to rotate about an axis in horizontal parallelism with the path of said material, but vertically inclined relatively at an acute angle in the direction of travel thereof.

JAMES DUVALL. 

